tests/stream_flash: Disable SPI_NOR on nrf54l devices

The stream flash test has been written with SoC internal
storage in mind and its simplified structure does not take
into account possibility of existence of devices with
different erase characteristics, at run time.
The commit fixes the test failing with Nordic bords that
have CONFIG_SPI_NOR=y set by default, which made test
to behave like device with erase capability has been tested.

The commit sets CONFIG_SPI_NOR=n for nrf54l devices.

Fixes #79181

Signed-off-by: Dominik Ermel <[email protected]>

Author: de-nordic

tests/subsys/storage/stream/stream_flash/testcase.yaml

@@ -15,6 +15,8 @@ tests:
   storage.stream_flash.no_explicit_erase:
     platform_allow:
       - nrf54l15dk/nrf54l15/cpuapp
+    extra_args:
+      - CONFIG_SPI_NOR=n
   storage.stream_flash.dword_wbs:
     extra_args: DTC_OVERLAY_FILE=unaligned_flush.overlay
     tags: stream_flash